Bacteria types vary widely in tumors of people with early vs. late-onset colorectal cancer

Researchers at Georgetown University's Lombardi Comprehensive Cancer Center studied the microbiome of people with colorectal cancer and found the make-up of the bacteria, fungi and viruses in a person’s tumor varied significantly depending on whether they were diagnosed with early-onset disease (age 45 or younger) or late-onset disease (age 65 or older).

To better understand the role of the microbiome and how its influence varies depending on a person’s age of onset of colorectal cancer, Weinberg and colleagues looked at the DNA and the microbiome of tumors from 36 patients with colorectal cancer who were diagnosed before age 45 as well as specimens from 27 people who were diagnosed after age 65.

Overall, the investigators detected 917 unique bacterial and fungal species in the tumors. One of the most common bacteria found was F. nuc, which appeared equally in about 30% of both early and late-onset tumors. Differences were seen in Cladosporium sp., which was found more commonly in early-onset disease, whereas Pseudomonas luteola, Ralstonia sp., and Moraxella osloensis were seen more commonly in late onset disease. In terms of composition, Clostridium perfringens, Escherichia coli, Leptotrichia hofstadii, Mycosphaerella sp., Neodevriesia modesta, Penicillium sp., and Leptosphaeria sp., each made up 11% of the microbiome in people with late-onset disease but these organisms were not found at all in people with early-onset disease.

Weinberg says with the current data, and with future efforts to collect more samples, they anticipate expanding their research efforts to continue exploring the relationship between the microbiome and other factors that contribute to colorectal cancer.

Reference:

Comprehensive study of the intratumoral microbiome in early- vs. late-onset colorectal cancer: Final analysis of COSMO CRC.